Roll system



Dec. 16, 1952 A. NlELD 2,621,390

ROLL SYSTEM Filed April 12, 1948 2 SPEETSSHEET 1 JNVENTOR. &RNOLD NIE-LDATTORNEY A. NIELD ROLL SYSTEM Dec. 16, 1952 Filed April 12, 1948 2SHEETS-SHEET 2 mm m WE vw mm MD R. w M

Patented Dec. 16, 1952 UNITED STATES ATENT OFFICE ROLL SYSTEM tion ofGreat Britain Application April 12, 1948, Serial No. 20,481 In GreatBritain April 14, 1947 12 Claims.

This invention relates to an improved roll system which enables afilamentary material e. g. a yarn, filament, wire, cord, tape, ribbon orband to make adequate frictional contact with a moving roll surfacewithout encircling the moving roll. More particularly it relates to animproved roll system for use in the conveying of yarns and filaments andis of particular interest in relation to roll systems where the rollsrotate at high speeds e. g. in the drawing or winding of artificialyarns and filaments.

It is necessary during the conveying of filamentary materials by meansof roll systems to prevent slipping over the surface of the drivingrolls. One method of doing this is to use a nip roll in conjunction withthe driving roll, the filamentary material being pinched between nip anddriving roll. This method has the objection that the roll surfacesundergo considerable wear owing to the friction occasioned between thedriving roll and the nip roll. As soon as the surfaces of the rollswear, inequalities in the pinching force are produced and these lead toslipping and thus to variation in the rate of movement of thefilamentary material. This is particularly noticeable in the textiletrade where, to prevent damage to the yarn or filament and to giveadequate frictional control, the nip rolls have a soft surface e. g.rubber, and this is worn away very quickly. Another method of preventingslippage frequently used in the textile trade is to use a single idlerroll the axis of which is slightly off parallel with that of the drivingroll, so that a filamentary material e. g. a yarn looped a number oftimes round the two rolls makes a number of loops round the rollswithout overlapping and thereby makes contact with the driving roll overa comparatively large arc of the circumference thereof, the total of anumber of arcs of contact being often equivalent to more than onecomplete turn round the driving roll.

Referring particularly to the textile trade, it is common practice inthe art to subject artificial yarns and filaments to a drawing process.In the commercial drawing of artificial yarns and filaments it is usualto use a battery of feed roll/draw roll systems on one supporting metalframe, all driving rolls being connected by gears to a main drivingshaft. This apparatus has the disadvantage of under-going considerablevibration and as a result of this, in conjunction with the inevitableslight mechanical inaccuracies in the gearing there is a tendency forthe apparatus to produce inequalities in the degree to which the yarn orfilament is drawn. To overcome this difficulty it has been proposed touse one shaft, running the length of the supporting frame, carry ing allfeed rolls, and a similar shaft, capable of rotating at higher speeds,carrying the same number of draw rolls. Such an apparatus needs far lessgearing and undergoes less vibration than that normally used butdifliculty is experienced in stringing up each driving roll and itsattendant idler roll as the stringing up operation normally takes placewhile the rolls are in motion and the yarn or filament has to be passedinto the interior portion of the machine and near the moving parts toencompass the driving roll and its idler roll, while the shaft on whichthe driving roll is mounted is rotating at a high speed. This stringingup operation is difficult and may be dangerous for the operator. Niprolls have been used with such a drawing apparatus and while they may besatisfactory in conjunction with feed rolls I find that owing to thehigh rate of wear they are not satisfactory when used in conjunctionwith draw rolls.

An object of this invention is to provide an improved roll system toenable a filamentary material e. g. a yarn, filament, wire, cord, tape,ribbon or band which makes frictional contact with a moving roll surfaceto make adequate frictional contact without encircling the moving roll.A further object is the production of an improved roll system for use inthe conveying of filamentary material which can be strung up more easilythan those of the prior art. A still further object is the provision ofan idler roll device for use in the drawing of artificial yarns andfilaments and the winding of textile yarn and filamentary materials. Yeta still further object is the provision of an idler roll device for usein conjunction with draw frames having a series of draw rolls mounted onone continuous shaft. Further objects will appear hereinafter.

According to the present invention these objects are accomplished by theprovision of a roll system comprising an idler roll and a driving roll,the axes of which are substantially parallel, characterised in that italso comprises means for ensuring that filamentary material when beingtransported by the roll system and encompassing said idler roll, makesarcs of contact with but does not encircle the driving roll and meansfor ensuring that the filamentary material makes more than one loopround the idler roll without overlapping.

The means for ensuring that filamentary material encompassing the idlerroll makes arcs of contact with but does not encircle the driving roll,preferably consists of one or more additional 3 idler rolls which areall encompassed by the filamentary material in the manner illustrated inthe attached drawings. It will be appreciated that one or more of theseadditional idler rolls may be replaced by other supporting means such asbars or guides.

In a preferred embodiment of this invention the idler roll together withany additional supporting means is so mounted that either the idler rollor the additional supporting means or both may be swung or otherwisemoved away from the driving roll during stringing up. Utilising thisapparatus the roll system may be strung up-very easily, the filamentarymaterial being wound round the idler roll and other supporting meanswithout any contact being made with the moving driving roll and broughtinto contact with the driving roll after the system has been strung up.A similar effect may be achieved if desired by moving the driving rollbut it will be appreciated that this involves more difficulty in machinedesign and greatly increases the cost of the machine.

The means for ensuring that the filamentary material makes more than oneloop round the idler roll may be any of the known spacing devices suchas combs or a number of guides which separate the various loops offilamentary material. A preferred method of operation is to mount one ofthe idler rolls used, slightly 01? parallel with the other supportingmeans so that it acts as a skew or oblique roll. Another method ofoperation is the use of ridged or grooved idler rolls or supports. Boththe last two methods have the advantage of combining a spacing meanswith a supporting means.

In the attached drawings'Figure l'is a diagram illustrating the generalapplication of the roll system of this invention. The filamentarymaterial l passes to, but does not encircle, the driving roll 2 and isheld in contact with the roll 2 over the arc ab by causing it tofollow'the path shown in the drawing round the two idler rolls 3 and 4.From the idler roll 4 the filamentary material passes to a furthertreating zone or normal collecting device. The filamentary materialmakes a number of loops round the idler rolls 3 and 4 to increase thefrictional grip between the filamentary material and the roll 2, and toprevent overlapping of the various loops the axis of rotation of theroll 3 is set just off parallel with the rolls 2 and 4.

Figure 2 illustrates a preferred form of the device of this inventionapplied to the drawing of artificial yarn, wherein yarn licoming fromthe feed rolls (not shown) makes four turns round the threeidler' rolls6, l and 8 (roll 3 is slightly off parallel to enable the yarn passinground the rolls 5, I and 8 to make a number of turns withoutoverlapping) during which it is held against the driven draw roll 9 andfinally passes from the idler roll 8 to a collecting device (not shown).The three idler rolls are mounted on stub axles which are fastened to aframe Hi which can swivel about axle ll set in the bracket l3 which isattached to the frame of the drawing apparatus. The frame it is fittedwith a spring device 12 which presses against the bracket 13 and holdsthe frame It in the position required for the yarn to make the necessaryarcs of contact with the draw roll 9.

Figure 3 shows an end view of Figure 2 in which the path of yarnroundthe rolls 6, T, 8 and 9 can be clearly seen, the yarn makingcontact with the draw" roll over the arc my. It will be appreciated 4that the yarn actually makes four arcs of contact with the draw rollsurface.

Figure 4 shows an end view of Figure 2 wherein the frame It has beenswung away from the driven draw roll 9 about the axle H by pulling thehandle it and thus releasing the spring device 12. It will be seen fromthis drawing how the yarn can be wrapped round the idler rolls withoutany contact being made with the moving draw roll which, on the preferredtype of draw frame, is one of a series mounted on one continuous drivenshaft. To start the drawing process, after the yarn has been wound anumber of times round the idlers and passed to the collecting device,pressure is applied to the handle l4 and the frame swung into theposition shown in Figure- 3 where it is held by the spring device Thefour arcs of contact the yarn makes with the draw roll provide anadequate frictional grip, and slip over 'the draw roll surface isreduced to a minimum. This enables the draw ratio to be exactlycontrolled.

While in the foregoing description, devices using two and three idlerrolls are illustrated, any number of idler rolls may be used. I havefound that two or three idler rolls are very satisfactory as when two orthree are used it is possible to obtain large arcs of contact withsimple construction. The use of more than three rolls increasesmanufacturing costs and the complexity of the apparatus. The idler rollsmay if desired make contact with the driven roll but it is preferredthat they do not do so as such contact is liable to cause excessive wearand also complicates the design of the apparatus.

When supporting means other than idler rolls are used, care must betaken to ensure that the frictional force evoked by the passage of thefilamentary material over the supporting means is less than thefrictional grip of the filamentary material in contact with the drivingroll, otherwise slippage over the driving roll surface will occur. Thefrictional force at the supporting means surface will depend on the arcof contact of the filamentary material, the material of the supportingmeans and the filamentary material itself. It is therefore advisablethat not more than one supporting means other than idler rolls should beused. A further disadvantage of nonrotating supporting means is the wearcaused by the filamentary material slipping over the support surface.Such supports must therefore either be con=tructed of speciallyhardwearing material or replaced frequently. Both courses of action tendtoincrease the cost of the machinery.

While the method used in the drawings for withdrawing the idler rollsfrom the driving roll 15 one preferred for use with the device of thisinvention, it will be appreciated that the rolls may be withdrawn by anyusual means, they may for example be slid away from the driving rollalong suitable guides. Furthermore it is not necessary that all theidler rolls or other supporting means should be withdrawn from theproximity of the driving roll. Any number may be withdrawn dependingupon the type of mountmg used. For example two idler rolls may bemounted on arms which can be moved from the proximity of the driven rollby means of a scissors action. This type of mounting has the advantagethat it can be set up so that the pull of the filamentary material holdsthe idler rolls in close proximity to the driving roll since the pathtraversed by the filamentary material while in contact with the drivingroll is shorter than the path when the filamentary material is out ofcontact with the driving roll. The construction of the apparatus maytherefore be simplified since no holding device such as the springdevice illustrated in the drawings is required.

The spring device used to hold the idler roll device illustrated in thedrawings in position may be replaced by any holding device which willmaintain the filamentary material in contact with the driving roll e. g.a bolt, a latch or a weighted balance arm.

The path of the filamentary material round the idler rolls and othersupporting means will depend upon the mounting thereof and the directionof rotation of the driving roll. The number of loops of filamentarymaterial will depend upon the frictional grip required i. e. referringto the drawing of yarns, for heavy yarns more loops will be requiredthan for lightweight yarns.

The amount of contact of the filamentary material with the driving rolldepends to some extent on the disposition of the idler rolls or othersupporting means. The greater the arc of contact the filamentarymaterial makes with the driving roll the more efiicient is the systemand it is preferred that the arc of contact should be at least 90 ateach pass over the driving roll. However a smaller arc of contact maygive adequate grip if the number of loops of filamentary material isincreased accordingly.

While the idler roll device of this invention had been described withparticular reference to roll systems used for the conveying of yarns itwill be appreciated that it may be applied with equal success to allcases Where it is desirable to avoid winding any filamentary materialround a driving roll i. e. to avoid using a capstan grip, while ensuringthat the filamentary material does not slip over the roll surface. Sucha roll system may be used for example in the textile trade for thegripping of yarns, filaments, ribbons and braids, in the rope trade forthe gripping of ropes and cordage of all kinds and in the metal tradefor the gripping of Wires, cables and metal bands and strips.

While in the description the driving rolls referred to all have planesurfaces this is not essential. In the conveyin of wire for exampleadded frictional grip may be provided by the use of grooved rolls. Suchgrooves as well as serving to provide additional frictional grip alsoact as means for causing the filamentary material to make a number ofloops round the idler rolls without overlapping.

The device of this invention may be constructed to any of the materialscommonly used in the production of roll machinery. It will however beappreciated that th type of roll surface required is dependent on thetype of filamentary material. In the textile trade good results havebeen obtained using steel rolls or rolls made of light weight alloys e.g. aluminium alloys having a chromium plated surface.

The following examples illustrate but do not limit the scope of myinvention.

Example I idler rolls were mounted at one end of a plate, which was freeto swing about its other end in a plane at right angles to the axes ofrotation of the polished metal draw roll (3" diameter 6" long), and wereso positioned on the plate that their axes of rotation contacted theplate at the apices of a triangle, one axis being 3 to 4 olf parallelwith the other two which were parallel to the axis of rotation of thedraw roll as illustrated in Figures 2, 3 and 4. This plate was held sothat the idler rolls were well away from the draw roll during stringingup but was thereafter swung into a position with the idler rollsarranged round the draw roll so that yarn passing in a triangular pathround. the idler rolls was forced into contact with the draw roll on oneside of said triangle as illustrated in Fig. 3. The feed roll of thisapparatus rotated at revs. per minute, the draw roll at 600 revs. perminute. The yarn produced had a ratio drawn length to undrawn length of4.95:1 which indicates that there was a minimum amount of slip over thedraw roll surface.

Example 2 In this example a device similar to that illustrated inFigures 2, 3 and 4 was used but the third roll I was removed so thatonly two idler rolls were used.

A viscose yarn was taken from a package via suitable guides and woundthree times round two idler rolls, each 2 inches in diameter, and one01' which was slightly off parallel, mounted on a movable frame asillustrated in Figures 2, 3 and 4, without making contact with thedrawing roll. From the idlers the yarn passed through a lappet eye to arin twisting spindle capable of rotating at 6000 revs. per minute. Afterstringing up the yarn, the spindle was set in motion and the idler rollsupporting frame swung over so that the filamentary material madecontact with the driving roll, rotating at a surface speed of 50 feetper minute. A twist of 10 turns per inch was imparted to the yarn whichshowed no tendency to slip over the driving roll which in this caseacted as a feed roll.

I claim:

1. A process for forwarding artificial filamentary material by contactof said filamentary material with a driving roll which comprises loopingthe filamentary material round an idler roll and at least one additionalsupport, which idler roll and support are positioned so that thefilamentary material looped round them does not make contact with thedrivin roll, and then changing the position of at least one of themembers of the group, idler roll, additional support and driving roll sothat the filamentary material looped round the idler roll and additionalsupport is caused to make arcs of contact with the driving roll, whilesaid idler roll and additional support are maintained in spaced relationfrom said driving roll throughout their axial extent.

2. A process according to claim 1 wherein the additional support isanother idler roll.

3. A process according to claim 1 wherein the idler roll and theadditional support can be moved as one unit in relation to the drivingroll.

4. A process according to claim 1 wherein the arcs of contact made bythe filamentary material do not overlap.

5. A process according to claim 1 wherein the filamentary material is anartificial yarn or filament.

6.; Aprocessgaccording toclaim- 1 wherein the driving roll isadraw-roll.

7- Aprocess. of drawing artificial iyarns and filaments wherein the yarnor filament coming from feed rolls is. loopedrround a supportingdevice-comprising at leastone idler roll,.th axis of which issubstantially parallel to a driven drawroll, and one other idler rollskewed in relation to-the first idler; and thereafter causing the loopedfilamentary-material to make arcs of contact with the driving draw-rollbut Without permitting contact between said' idler rolls and draw-rollby changing th'eposition of the idler-rolls relative tothe-drawrolls,and then passing theryarn or filament toa suitablecollecting device.

8,. Apparatus-{or forwarding filamentary material comprisingsa frame. a,driving. roll, a. bracket mounted upon: said; frame and movable from aninoperative to operative position with respect to said driving roll, aplurality of filament supporting elements mountedupon said bracket andextending along axes which are substantially parallel to the axis ofsaid driving roll, eachcoi said elements including a peripheral surfaceadapted to be engaged by filamentary material, at least one of saidelements being rotatable about its axis, said filament supportingelement being positioned on said bracket so that in both operative andinoperative positions throughout their axial extent the peripheries ofsaid elements will be spaced from the periphery of said drivin roll, andso that when the bracket is in the operative position filamentarymaterial looped round the filament supporting element makes arcs ofcontact with the driving roll.

9. Apparatus according to claim 8 in which there are two filamentsupporting elements both of which are rotatable about their axes.

10. Apparatus for forwarding filamentary material comprising a frame, adriving roll, a bracket mounted upon said frame and movable from aninoperative to an operative position with respect to said driving roll,two filament supporting elements mounted upon said bracket, the first ofsaid elements extending along an axis substantially parallel to the axisof the driving roll and the second of said elements extending along anaxis askew to the axis of the driving roll, each of said elementsincluding a peripheral surface adapted to be engaged by filamentarymaterial, both said elements beingrotatable about their axes, saidfilament supporting elements being positioned on said bracket so that inboth operative and inoperative positions throughout their axial extentthe peripheries of said elements will be spaced from the periphery ofsaid driving roll, and so that when the bracket is in the operativeposition filamentary material looped roundthe filament supportingelements makes arcs of contact with the driving roll.

11. Apparatus according to claim 8 wherein one of the supportingelements is a bar.

12. Apparatus according to claim 8-whereinat least one of the filamentsupporting elements is a guide.

ARNOLD NIELD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PA'IEN'I' Number Name Date 483,809 Leonard Oct. 4, 18921,803,475 Kampf May 5, 1931 2,002,994 Hartmann et a1. May 28, 19352,294,871 Sellner Sept. 1, 1942 2,424,400 Kronofi July 22, 19472,462,043 Neidel Feb. 15, 1949 FOREIGN PATENTS p Number Country Date219,635 Germany Mar. 2, 1910

